Helicopter step



FIG. 1 is a perspective view of the helicopter step showing our new design;

FIG. 2 is an end view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof; and

FIG. 6 is a bottom view thereof. 

The ornamental design for a helicopter step, substantially as shown. 